Structure and characterization of the lentiviral SCN1A -reporter used in the electrophysiological analyses. (A) The reporter comprised (5′ to 3′) a 1.2-kb upstream sequence, a 5′-untranslated exon, the 5′-end of the first coding exon, and, following the ATG start codon, Venus cDNA. (B) & (C) 201B7 neurons labeled for Venus (using a GFP antibody) and Nav1.1 (B) or GABA (C). (B) Open arrowheads indicate GFP-pseudopositive neurons lacking Nav1.1 staining. (C) GFP-positive neurons with (arrowhead) and without GABA staining (open arrowhead). Scale bars: 200 μm.